Supercalifragilisticexpialidocious said backwards. Originates from the Disney film 'Mary Poppins'. It is believed that if five different people say this word at once, the universe implodes and is replaced by a comic store.

"Of course you could say it backwards, which is dociousaliexpiliciousfragicalirupus, but that's going a little too far, don't you think?"